leu·​cism | \ ˈlü-ˌsi-zəm How to pronounce leucism (audio) \

Definition of leucism

: an abnormal condition of reduced pigmentation affecting various animals (such as birds, mammals, and reptiles) that is marked by overall pale color or patches of reduced coloring and is caused by a genetic mutation which inhibits melanin and other pigments from being deposited in feathers, hair, or skin

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Other Words from leucism

leucistic \ lü-​ˈsi-​stik How to pronounce leucism (audio) \ adjective

Examples of leucism in a Sentence

Recent Examples on the Web Instead, the coloration comes from a genetic condition called leucism, which is a partial loss of pigmentation that still leaves dark coloring in the animal’s eyes, tail hair and spots. Theresa Machemer, Smithsonian Magazine, "World’s Only Known White Giraffe Now Has a GPS Tracker," 27 Nov. 2020 The giraffe, in the Ishaqbini Hirola Conservancy in southeast Kenya, has a rare genetic condition called leucism that causes partial loss of pigmentation in its skin. NBC News, "Extremely rare white giraffe gets tracker after poachers killed its family," 18 Nov. 2020 Unlike albinism, animals with leucism continue to produce a dark pigment in their soft tissue, meaning the giraffe's eyes are dark. Eoin Mcsweeney, CNN, "World's only known white giraffe gets fitted with a tracking device," 17 Nov. 2020 The hatchling is believed to have a genetic condition called leucism, which causes animals to have reduced pigmentation. Fox News, "Rare sea turtle discovered on South Carolina beach in 'elusive' find," 19 Oct. 2020 According to the Olive Ridley Project, sea turtles with leucism are rare, largely because odds of survival in the ocean are slim. Meghan Overdeep, Southern Living, "Exceedingly Rare White Sea Turtle Hatches From South Carolina Nest," 21 Oct. 2020 Sea turtles with leucism have black eyes and a small amount of pigment on their skin. Fox News, "Rare sea turtle discovered on South Carolina beach in 'elusive' find," 19 Oct. 2020 The tope shark, or school shark, has a condition called leucism that results in loss of pigmentation. Chris Ciaccia, Fox News, "Rare all-white shark found: 'The fish of a lifetime'," 5 Oct. 2020 The animals’ unique white appearance was due to leucism, a condition that causes partial loss of pigmentation. Brigit Katz, Smithsonian Magazine, "Two Rare White Giraffes Killed by Poachers in Kenya," 12 Mar. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'leucism.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of leucism

1878, in the meaning defined above

History and Etymology for leucism

borrowed from German Leucismus, from Greek leukós "clear, white" + German -ismus -ism — more at light entry 1

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Time Traveler for leucism

Time Traveler

The first known use of leucism was in 1878

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Statistics for leucism

Cite this Entry

“Leucism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/leucism. Accessed 5 Mar. 2021.

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